Ever since King Tut’s lavish tomb was opened in 1924, when people weren’t muttering about the curse supposedly placed on it they were trying to divine what killed the young Egyptian king. Now, a British surgeon and history buff has a new theory about not only what may have caused King Tut’s death, but also led Egypt to become the world’s first monotheistic culture.

Hutan Ashrafian, a surgeon at Imperial College London, thinks the malady that killed King Tut was epilepsy. Ashrafian’s theory, reported in New Science, is the result of some good old fashioned historical deduction. The surgeon noted the pharaohs’ feminized figures, as they appeared in the artistic portrayals of King Tut and his presumed relatives — Smenkhkare, believed to be Tutankhamun’s uncle or older brother, and Akhenaten, who is thought to be Tut’s father. He also took into account findings that each pharaoh had died at a slightly younger age than his predecessor. To Ashrafian, this suggested an inherited disorder. Then Ashrafian looked at the religious events that occurred under these pharaohs’ watch. “It’s significant that two [of the five related pharaohs] had stories of religious visions associated with them,” Ashrafian told New Science. The religious experience of Tuthmosis IV is inscribed near the Great Sphinx, while Akhenaten’s religious vision encouraged him to raise the status of a minor deity called Aten into a supreme god — thus establishing the earliest recorded monotheistic religion.

For Ashrafian, this historical milestone was another clue to what may have killed boy king. “People with temporal lobe epilepsy who are exposed to sunlight get the same sort of stimulation to the mind and religious zeal,” Ashrafian told the Washington Post. “It’s likely that the family of pharaohs had a heritable form of temporal lobe epilepsy.” According to New Science, the temporal lobe is connected to parts of the brain involved in the release of hormones, and epileptic seizures are known to alter the levels of hormones involved in sexual development — which could explain why the pharaohs were depicted with wide hips and larger breasts than you would expect on a man. A seizure might also be to blame for Tutankhamen’s fractured leg, says Ashrafian — evidence of which had led some to speculate that Tut died from injuries sustained after a fall from his chariot.

But the new theory does not completely lay to rest speculation about the cause of death of King Tutankhamen. “It’s a fascinating and plausible explanation,” said Howard Markel, a medical historian at the University of Michigan in Ann Arbor, to the Washington Post. However, he notes, the theory is almost impossible to prove, given that there is no definitive genetic test for epilepsy. “Do we know that a seizure led to monotheism? It’s a nice idea, but we don’t know,” he says. “It’s a very interesting hypothesis, but it’s just that — there’s no definite proof.”